1,720,966 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
[Biliary-enteric anastomosis: role of cholangiography with magnetic resonance].
No full textOur study was aimed at investigating the role of MR-cholangiography (MRC) in the examination of patients treated with biliary-enteric anastomosis. MRC was performed in 15 patients (8 men and 7 women, mean age: 64.7 years) operated on for biliary-enteric anastomoses (13 hepaticojejunostomies and 2 choledochoduodenostomies) whose symptoms were as follows: persistent jaundice in 4 patients; cholangitis and abnormal liver function tests in 2 patients; associated transient jaundice, epigastric pain, abnormal liver function tests in 2 patients. The remaining 7 patients were asymptomatic and examined during their follow-up. MRC was performed with a non-breath-hold, fat-suppressed 3D turbo spin echo sequence (TR = 3000 msec, TE = 700 msec, ETL = 128) with an acquisition time ranging 4 min 24 sec to 5 min 48 sec. Six patients were subsequently submitted to Percutaneous Transhepatic Cholangiography (PTC) to confirm the diagnosis and to perform a therapeutical procedure. Two patients, submitted to choledochoduodenostomy were examined with ERCP. The remaining seven patients, examined during their surgical follow-up and who presented no major symptoms or dilation of the bile ducts, were not submitted to any invasive procedure. Image quality was graded as good to fair in 12/15 cases (80%) and poor in 3/15 cases (20%). The degree of bile ducts dilation was correctly assessed with complete inter observer agreement in 8/8 patients. MRCP correctly showed: bile ducts irregularities in 2 of 4 patients with cholangitis (k = 0.59), anastomosis stenosis in 8 of 8 patients (k = 0.86), and 5-15 mm stones in 5 of 5 patients (k = 0.95). In conclusion, MRCP is a safe, noninvasive technique in the study of biliary-enteric anastomoses with high accuracy in assessing the cause of jaundice. MRCP images can be used as a guide for subsequent interventional procedures. Its main disadvantages are the lack of functional information and the high cost which limits its its use to the screening of symptomatic patients
[Animal experimentation in radiology. Objectives, organizational and ethical problems].
No full textThe contribution of biomedical sciences to the scientific breakthroughs in the last years has benefitted also by experiments on animals. As for diagnostic imaging, the use of new contrast media for angiography, CT and MRI makes it necessary, according to the law, to perform preliminary animal studies to test efficacy, pharmacokinetics and pharmacodynamics of the contrast agents. Experimental animal studies of clinically well-established contrast agents are also justified by the need to implement new imaging modalities. The close relationship between medical research and animal experimentation has awakened public opinion, as well as the researchers themselves, to the ethical and legal problems related to animal testing. This paper reports on the regulations which are currently in use in this field
Percutaneous peritoneovenous shunt positioning: technique and preliminary results
No full textNine peritoneovenous shunts were positioned by percutaneous technique in seven patients with advanced malignancy causing severe refractory ascites, and in two patients with hepatic cirrhosis (one with hepatocarcinoma). In all patients the shunts were percutaneously placed through the subclavian vein in the angiographic suite under digital fluoroscopic guide. No complications directly related to the procedure occurred. The shunt was successfully positioned in all patients in 60 min average time. No patient showed symptoms related to pulmonary overload or to disseminated intravascular coagulation. All patients had a significant improvement of the objective symptoms related to ascites such as respiratory symptoms, dyspepsia, and functional impairment to evacuation describing an improvement of their quality of life. Maximum shunt patency was 273 days. Percutaneous placement of peritoneovenous shunt is a safe, fast, and inexpensive procedure, extremely useful in resolution of refractory ascites, reducing symptoms, and allowing effective palliation, with a great improvement in quality of life
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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